style.css

body {
    background-image: url("dot-grid.png");
    background-repeat: repeat;
    font-family: serif;
    line-height: 150%;
}
div {
    margin-left: auto;
    margin-right: auto;
    max-width: 20em;
    font-size: 110%;
    text-align: justify;
}
p {
    max-width: 29em;
    text-align: justify;
    margin-top: 5px;
}
h1 {
    font-size: 200%;
    line-height:normal;
}
h3 {
    text-align: left;
    margin-bottom: 0;
    padding-bottom: 0;
}
sup {
    font-family: sans-serif;
    font-weight: bold;
    font-size: x-small;

}
figcaption {
    font-family: serif;
    color: dimgray;
    font-size: 70%;
    max-width: 15em;
    line-height: normal;

}
sub {
    padding-top: -5px;
    padding-bottom: 10px;
}
.center {
  display: block;
  margin-left: auto;
  margin-right: auto;
    width: 100%
}
em {
    background: #fefd80;
    border: 20px solid #fefd80;
    float: left;
    text-align: left;
    font-style:normal;
    margin-bottom: 20px;
}
hr {
    border: .1px;
    color: black;
    border-style: dashed;
    margin-bottom: 1em;
}